1. Field of the Invention
This invention relates to an image processing apparatus and, more particularly, to an image processing apparatus for adjusting the lightness of an input image.
2. Description of the Prior Art
In general, the image contrast refers to the lightness ratio between a light zone and a dark zone within an image. Enhancing the contrast of an image sometimes makes the image distorted a little. But, for most of people, adequately enhancing the image contrast will derive a desirable image.
Most of displays can offer users to adjust the image contrast or provide the Gamma factor for users to select, so as to improve the image contrast. But the constant image contrasts are usually unavailable to different images. For example, for the image whose whole lightness is much higher, users can select a larger Gamma factor or change the image contrast to enhance the contrast of the image. But the same image contrasts applied to the image whose lightness is lower may cause the dark portion of the image to lose the niceties, so as to make the quality of the image worse.
Accordingly, the major scope of the inventor is to provide an image processing apparatus to solve the foregoing problems.